Pseudostratified columnar epitheliumA pseudostratified epithelium is a type of epithelium that, though comprising only a single layer of cells, has its cell nuclei positioned in a manner suggestive of stratified epithelia. As it rarely occurs as squamous or cuboidal epithelia, it is usually considered synonymous with the term pseudostratified columnar epithelium. The term pseudostratified is derived from the appearance of this epithelium in the section which conveys the erroneous (pseudo means almost or approaching) impression that there is more than one layer of cells, when in fact this is a true simple epithelium since all the cells rest on the basement membrane.
Stomach cancerStomach cancer, also known as gastric cancer, is a cancer that develops from the lining of the stomach. Most cases of stomach cancers are gastric carcinomas, which can be divided into a number of subtypes, including gastric adenocarcinomas. Lymphomas and mesenchymal tumors may also develop in the stomach. Early symptoms may include heartburn, upper abdominal pain, nausea, and loss of appetite. Later signs and symptoms may include weight loss, yellowing of the skin and whites of the eyes, vomiting, difficulty swallowing, and blood in the stool, among others.
Oral candidiasisOral candidiasis, also known as oral thrush among other names, is candidiasis that occurs in the mouth. That is, oral candidiasis is a mycosis (yeast/fungal infection) of Candida species on the mucous membranes of the mouth. Candida albicans is the most commonly implicated organism in this condition. C. albicans is carried in the mouths of about 50% of the world's population as a normal component of the oral microbiota. This candidal carriage state is not considered a disease, but when Candida species become pathogenic and invade host tissues, oral candidiasis can occur.
Basal laminaThe basal lamina is a layer of extracellular matrix secreted by the epithelial cells, on which the epithelium sits. It is often incorrectly referred to as the basement membrane, though it does constitute a portion of the basement membrane. The basal lamina is visible only with the electron microscope, where it appears as an electron-dense layer that is 20–100 nm thick (with some exceptions that are thicker, such as basal lamina in lung alveoli and renal glomeruli).
LeukoplakiaOral leukoplakia is a potentially malignant disorder affecting the oral mucosa. It is defined as "essentially an oral mucosal white lesion that cannot be considered as any other definable lesion." Oral leukoplakia is a white patch or plaque that develops in the oral cavity and is strongly associated with smoking. Leukoplakia is a firmly attached white patch on a mucous membrane which is associated with increased risk of cancer. The edges of the lesion are typically abrupt and the lesion changes with time.
Basement membraneThe basement membrane, also known as base membrane is a thin, pliable sheet-like type of extracellular matrix that provides cell and tissue support and acts as a platform for complex signalling. The basement membrane sits between epithelial tissues including mesothelium and endothelium, and the underlying connective tissue. As seen with the electron microscope, the basement membrane is composed of two layers, the basal lamina and the reticular lamina.
Oral mucosaThe oral mucosa is the mucous membrane lining the inside of the mouth. It comprises stratified squamous epithelium, termed "oral epithelium", and an underlying connective tissue termed lamina propria. The oral cavity has sometimes been described as a mirror that reflects the health of the individual. Changes indicative of disease are seen as alterations in the oral mucosa lining the mouth, which can reveal systemic conditions, such as diabetes or vitamin deficiency, or the local effects of chronic tobacco or alcohol use.
Endothelial cell tropismEndothelial cell tropism or endotheliotropism is a type of tissue tropism or host tropism that characterizes an pathogen's ability to recognize and infect an endothelial cell. Pathogens, such as viruses, can target a specific tissue type or multiple tissue types. Like other cells, the endothelial cell possesses several features that supports a productive viral infection a cell including, cell surface receptors, immune responses, and other virulence factors.
Caseous necrosisCaseous necrosis or caseous degeneration (ˈkeɪsiəs) is a unique form of cell death in which the tissue maintains a cheese-like appearance. It is also a distinctive form of coagulative necrosis. The dead tissue appears as a soft and white proteinaceous dead cell mass. The word caseous means 'pertaining or related to cheese', and comes from the Latin word caseus 'cheese'. Necrosis refers to the fact that cells do not die in a programmed and orderly way as in apoptosis.
